Vehicle collision determination apparatuses are known as disclosed, for example, in Japanese Patent Application Laid-open Publication (JP-A) No. 2006-044432. The vehicle collision determination apparatus disclosed in JP 2006-044432 takes the form of a vehicle occupant protection apparatus equipped with a front G sensor, a floor G sensor, and an airbag deployment determination means. The front G sensor is mounted to a front part of a vehicle (radiator core supporting a radiator), and the floor G sensor is disposed at substantially the center of a cabin of the vehicle. The airbag deployment determination means includes a subtraction means which can calculate the difference between a time-integrated value of an output (deceleration) of the front G sensor and a time-integrated value of an output (deceleration) of the floor G sensor, thus calculating attenuation amount of the output (deceleration) of the front G sensor. The airbag deployment determination means performs calculation of the difference in order to determine the collision mode when a frontal collision occurs.
The collision determination apparatus disclosed in JP 2006-044432 is, however, not fully satisfactory in that the airbag deployment determination means cannot discriminate a high-speed ODB (offset deformable barrier) frontal collision where the vehicle is made to collide head-on on the driver's side with an aluminum honeycomb structure at 64 km/h and a slant head-on collision where the vehicle is made to collide head-on on the driver's side with a slanting concrete barrier at 48 km/h. The severity of the high-speed ODB frontal collision is therefore determined as being “high”. Furthermore, when the vehicle is made to collide with a concrete barrier at 37 km/h, the severity of such frontal collision is determined as being “low”.
It is therefore an object of the present invention to provide a vehicle collision determination apparatus which is capable of protecting a vehicle occupant more appropriately. Other objects of the invention will become apparent to a person skilled in the art from the following description of preferred embodiments taken in conjunction with the accompanying drawings.